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Cubesat Adcs Validation And Testing Apparatus, Jacob Stevens 2016 Western Michigan University

Cubesat Adcs Validation And Testing Apparatus, Jacob Stevens

Honors Theses

The WALI team at Western Michigan University requested a test environment to validate their CubeSat’s de-tumbling control system and hardware. The test environment required a Helmholtz cage and spherical air bearing. The Helmholtz cage provides an adjustable magnetic field to simulate low earth orbit; the spherical air bearing simulates the friction free environment the CubeSat will experience in space. In conjunction, the two components create an adjustable system that simulates a satellite in low earth orbit.


Development Of Cal Poly's Shock Table, Christopher D. Risner 2016 California Polytechnic State University - San Luis Obispo

Development Of Cal Poly's Shock Table, Christopher D. Risner

Master's Theses and Project Reports

Shock is one of the environmental tests that a spacecraft must pass before being cleared for launch. Shock testing poses a challenging data acquisition issue and careful selection of equipment is crucial to creating a successful shock test facility. Cal Poly’s CubeSat programs can currently perform all environmental testing other than shock themselves, so a quality shock table would be useful. Previous groups of students had developed a shock table, and this paper details the improvement and characterization of that shock table’s behavior. Several adjustable parameters were tested and documented to discover trends in the shock table’s ...


Nanostructured Morphologies In Glassy Polymer Networks, Brian Greenhoe 2016 University of Southern Mississippi

Nanostructured Morphologies In Glassy Polymer Networks, Brian Greenhoe

Dissertations

The body of this work describes a novel approach for the dispersion of multi-walled carbon nanotubes in a high Tg epoxy prepolymer matrix using a twin screw high-shear continuous reactor. The method demonstrated improves on previous dispersion methods in several ways. It offers increased efficiency through excellent heat transfer, while being solvent-less, scale-able, and tailorable to drive dispersion states to judiciously chosen dispersion states. Furthermore, it was shown that dispersion state and agglomerate morphology can be directed, in several ways, through processing conditions and also by controlling the matrix viscosity profile through cure. Broadband dielectric spectroscopy, optical hot-stage microscopy ...


Microstructural Analysis Of Thermoelastic Response, Nonlinear Creep, And Pervasive Cracking In Heterogeneous Materials, Alden C. Cook 2016 University of Maine

Microstructural Analysis Of Thermoelastic Response, Nonlinear Creep, And Pervasive Cracking In Heterogeneous Materials, Alden C. Cook

Electronic Theses and Dissertations

This dissertation is concerned with the development of robust numerical solution procedures for the generalized micromechanical analysis of linear and nonlinear constitutive behavior in heterogeneous materials. Although the methods developed are applicable in many engineering, geological, and materials science fields, three main areas are explored in this work. First, a numerical methodology is presented for the thermomechanical analysis of heterogeneous materials with a special focus on real polycrystalline microstructures obtained using electron backscatter diffraction techniques. Asymptotic expansion homogenization and finite element analysis are employed for micromechanical analysis of polycrystalline materials. Effective thermoelastic properties of polycrystalline materials are determined and compared ...


Simulation Investigation Of Temperature Distribution In Large Aluminium Panel During Autoclave Age Forming Process, Yongqian Xu 2016 Central South University

Simulation Investigation Of Temperature Distribution In Large Aluminium Panel During Autoclave Age Forming Process, Yongqian Xu

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Multi-Dome Forming Of A Ti–Al–Mn Alloy, Sergey Aksenov, Aleksey Kolesnikov, Ivan Zakhariev 2016 National Research University Higher School of Economics

Multi-Dome Forming Of A Ti–Al–Mn Alloy, Sergey Aksenov, Aleksey Kolesnikov, Ivan Zakhariev

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


From Xst To F-117a, Alan Brown 2016 Embry-Riddle Aeronautical University

From Xst To F-117a, Alan Brown

ERAU Prescott Aviation History Program

Learn the remarkable story of stealth technology from the man often referred to as “Mr. Stealth.” From 1975-1989 Alan Brown was a member of Lockheed “Skunk Works”, becoming program manager & chief engineer for the F-117A Stealth Fighter from initial concept until the first production aircraft was built, 1978 to 1982. Hear the inside story of the many challenges faced by the stealth program and how they were solved.


Experimentation Of Mode I & Mode Ii Fracture Of Uni-Directional Composites And Finite Element Analysis Of Mode I Fracture Using Cohesive Contact, Joseph Daniel Garrett 2016 California Polytechnic State University, San Luis Obispo

Experimentation Of Mode I & Mode Ii Fracture Of Uni-Directional Composites And Finite Element Analysis Of Mode I Fracture Using Cohesive Contact, Joseph Daniel Garrett

Master's Theses and Project Reports

As the use of fiber-reinforced composites has increased over the decades, so has the need to understand the complexity of their failure mechanisms as engineers seek to improve the damage tolerance of composite laminated structures. One of the most prevalent and limiting mode of failure within composite laminates is delamination, since it not only reduces a structures stiffness and strength, but can be very difficult to detect without the use of special non-destructive equipment. Industry testing organizations have utilized several fracture tests in order to characterize the fracture toughness of composite materials under different loading conditions. For this research, ASTM ...


Metamodels Of Residual Stress Buildup For Machining Process Modeling, Stuart B. McCrorie, Michael Sangid 2016 Purdue University

Metamodels Of Residual Stress Buildup For Machining Process Modeling, Stuart B. Mccrorie, Michael Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

In the process of machining materials, stresses, called residual stresses, accumulate in the workpiece being machined that remain after the process is completed. These residual stresses can affect the properties of the material or cause part distortion, and it is important that they be calculated to prevent complications from arising due to the residual stresses. However, these calculations can be incredibly computationally intensive, and thus other methods are needed to predict the residual stresses in materials for quick decision-making during machining. By using metamodels - a method of representing data where few data points exist - we can achieve an accurate prediction ...


Evaluation Of Strain Distortion Correction Protocol Using Scanning Electron Microscopy And Digital Image Correlation, Alexandra Mallory, Alberto Mello, Michael Sangid 2016 San Diego State University

Evaluation Of Strain Distortion Correction Protocol Using Scanning Electron Microscopy And Digital Image Correlation, Alexandra Mallory, Alberto Mello, Michael Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

Scanning electron microscopy in combination with digital image correlation (SEM-DIC) is a useful technique for measuring strain in materials at the micro-scale. In particular, it can be used to identify micro-scale strain localizations that are the precursor to material failure. While SEM produces high resolution images of the microstructure, the images also contain a large amount of distortion that, during DIC, will result in distorted strain values that require correction. In this project, a nickel-based alloy underwent cyclic mechanical fatigue at three different high temperatures to a targeted maximum strain. Scanning electron microscopy imaging was done on a 200x150μm area ...


Statistical Impact-Echo Analysis Using Bag-Of-Echoes Model For Concrete.Pdf, Jacky Yin 2016 Hongkong Baptist university

Statistical Impact-Echo Analysis Using Bag-Of-Echoes Model For Concrete.Pdf, Jacky Yin

Jacky Yin

In recent years, advancement in information technologies, i.e. cloud service and high speed wireless network, greatly facilitate the large collection of structural health monitoring (SHM) data. In order to effectively exploit massive sensor data for accurate condition assessment of infrastructures, there has been increasing interest in application of statistical pattern recognition methods in the field of SHM. This paper addresses development of efficient pattern analysis scheme for impact-echo test, which is one of the most conventional nondestructive test (NDT) methods. The proposed scheme stems from Bag-of-feature (BoF) model, which has been successfully applied for natural language processing and computer ...


Ultrasonic Sol-Gel Arrays For Monitoring High-Temperature Corrosion, Thomas J. Eason, Leonard J. Bond, Mark G. Lozev 2016 Iowa State University

Ultrasonic Sol-Gel Arrays For Monitoring High-Temperature Corrosion, Thomas J. Eason, Leonard J. Bond, Mark G. Lozev

Center for Nondestructive Evaluation Conference Papers, Posters and Presentations

Corrosion of oil refinery equipment operating at high temperature is a growing challenge linked to an increase in sulfur concentration and acidity within the world supply of crude oils. Improved high temperature monitoring tools are needed to continuously measure the local minimum wall thickness of steel pipe subject to non-uniform internal corrosion. Thickness measurements must be sufficiently accurate to calculate the maximum allowable stress permissible as to avoid failure. Thickness measurements must also be sufficiently reliable and precise to correlate the rate of wall-loss with process conditions as to improve future corrosion rate predictions. Permanently installed structural health monitoring (SHM ...


Predicting Flexural Strength Of Composite Honeycomb Core Sandwich Panels Using Mechanical Models Of Face Sheet Compressive Strength, Nicholas Bruffey, William Shiu 2016 California Polytechnic State University, San Luis Obispo

Predicting Flexural Strength Of Composite Honeycomb Core Sandwich Panels Using Mechanical Models Of Face Sheet Compressive Strength, Nicholas Bruffey, William Shiu

Materials Engineering

The design process at Zodiac Aerospace requires the ability to accurately predict the strength of a composite honeycomb core sandwich panel to adhere to strict FAA regulations. The most common failure mode in long beam composites is in compression. Following ASTM D7249 for a four-point bend test of a long beam flexural test, a mechanical model has been developed that relates the compressive strength of glass fiber face sheets to the flexural strength of the sandwich panel. Zodiac does not currently have data on the compressive strength of the face sheets, so testing was performed to find this property. Asymmetric ...


Effects Of Curing Cycle And Loading Rates On The Bearing Stress Of Double Shear Composite Joints, Mateja Andrejic 2016 California Polytechnic State University - San Luis Obispo

Effects Of Curing Cycle And Loading Rates On The Bearing Stress Of Double Shear Composite Joints, Mateja Andrejic

Master's Theses and Project Reports

In the last few decades, there has been a shift to using more lightweight materials for the potential of fuel consumption reduction. In the Aerospace Industry, conventional metal structures are being replaced by advanced composite structures. The major advantage of an advanced composite structure is the huge reduction in the number of parts and joints required. Also composite materials provide better resistance to creep, corrosion, and fatigue. However, one cannot eliminate all the joints and attachments in an aircraft’s structure. Eliminating structural joints is impractical in present-day aircraft because of the requirements for inspection, manufacturing breaks, assembly and equipment ...


Effect Of Low Velocity Impact On The Vibrational Behavior Of A Composite Wing, Richard M. de Luna 2016 California Polytechnic State University, San Luis Obispo

Effect Of Low Velocity Impact On The Vibrational Behavior Of A Composite Wing, Richard M. De Luna

Master's Theses and Project Reports

Impact strength is one of the most important structural properties for a designer to consider, but it is often the most difficult to quantify or measure. A major concern for composite structures in the field is the effect of foreign objects striking composites because the damage is often undetectable by visual inspection. The objective for this study was to determine the effectiveness of using dynamic testing to identify the existence of damage in a small scale composite wing design. Four different impact locations were tested with three specimens per location for a total of 12 wings manufactured. The different impact ...


Enhancement Of The Total Focusing Method Imaging For Immersion Testing Of Anisotropic Carbon Fiber Composite Structures, Ameni Aschy, Nicholas Terrien, Sébastien Robert, Mourad Bentahar 2016 CETIM

Enhancement Of The Total Focusing Method Imaging For Immersion Testing Of Anisotropic Carbon Fiber Composite Structures, Ameni Aschy, Nicholas Terrien, Sébastien Robert, Mourad Bentahar

Review of Progress in Quantitative Nondestructive Evaluation

Carbon fiber composite structures are becoming more important in the construction of aerospace structures and other industries because of their low weight and their remarkable mechanical properties. Hence, master these structures from conception, during and after their manufacturing, represents an important issue in NDE. The control and the repair of these advanced materials require an in-depth knowledge of composite structures and the reliable detection of defects like delaminations, inclusions, porosities and stacks of resin, is increasingly important. In the present work, such defects are imaged with the Total Focusing Method (TFM) associated with a ray-based model that takes into account ...


Expedient Airfield Runway Repair Using Folded Fiberglass Mat, Christopher Y. Tuan, Willaim C. Dass 2016 University of Nebraska-Lincoln

Expedient Airfield Runway Repair Using Folded Fiberglass Mat, Christopher Y. Tuan, Willaim C. Dass

Civil Engineering Faculty Publications

For expedient airfield runway repair, the US Air Force has developed a folded fiberglass mat to cover craters repaired with a well-compacted granular base material. The objective of this study was to evaluate the adequacy of using polymer plugs to anchor the mat to a repaired asphalt pavement for heavy aircraft operations. The effort consisted of materials testing, field experiments and analytical modeling. An 89,800-kg (198,000-pound) load cart having the footprint of a single C-5 main gear was pulled on a mat with wheels locked to simulate full braking forces. Anchor bushings were instrumented to measure anchor loads ...


Model Benchmarking And Reference Signals For Angled-Beam Shear Wave Ultrasonic Nde Inspections, John C. Aldrin, Deborah Hopkins, Mark Warchol, Lyudmila V. Warchol, David S. Forsyth, Charlie Buynak, Eric A. Lindgren 2016 Computational Tools, Gurnee

Model Benchmarking And Reference Signals For Angled-Beam Shear Wave Ultrasonic Nde Inspections, John C. Aldrin, Deborah Hopkins, Mark Warchol, Lyudmila V. Warchol, David S. Forsyth, Charlie Buynak, Eric A. Lindgren

Review of Progress in Quantitative Nondestructive Evaluation

NDE modeling and simulation are important tools to support the development and validation of enhanced localization and characterization techniques. Previously, important achievements were made by the USAF to address crack detection in aircraft structures using angled-beam shear wave inspection techniques. However, new work on model benchmarking is needed to move beyond detection and achieve reliable crack characterization. To achieve this goal, simulated studies are needed to verify that models can accurately represent all of the key variables with the inspection of multilayer structures with fastener sites and varying crack conditions. Often with model benchmark studies, the accuracy of the model ...


Damage Evolution In 3d Woven Composite Materials Using Acoustic Emission, Matthieu Gresil, Mohamed Nasr Saleh, Constantinos Soutis, Mubeen Arshad 2016 University of Manchester

Damage Evolution In 3d Woven Composite Materials Using Acoustic Emission, Matthieu Gresil, Mohamed Nasr Saleh, Constantinos Soutis, Mubeen Arshad

Review of Progress in Quantitative Nondestructive Evaluation

Fibre-reinforced composite materials are used extensively in the aerospace industry because of their high specific strength and stiffness, superior corrosion resistance and improved fatigue properties. In addition to the manufacturing costs and production rates, damage tolerance has become a major issue for the composite industry. Three-dimensional (3D) woven composites have superior through-thickness properties compared to two-dimensional (2D) laminate, for example, improved impact damage tolerance, high interlaminar fracture toughness and reduced notch sensitivity. It is a big challenge to relate acoustic emission (AE) signal events to specific damage modes developed in composites under hygro-thermo-mechanical loading [1, 2]. This study provides further ...


Compton Imaging Tomography For Nondestructive Evaluation Of Large Multilayer Aircraft Components And Structures, Volodymyr Romanov, Victor Grubsky, Feraidoon Zahiri 2016 Physical Optics Corporation

Compton Imaging Tomography For Nondestructive Evaluation Of Large Multilayer Aircraft Components And Structures, Volodymyr Romanov, Victor Grubsky, Feraidoon Zahiri

Review of Progress in Quantitative Nondestructive Evaluation

Novel nondestructive evaluation (NDE) systems based on a recently pioneered Compton Imaging Tomography (CIT) technique [1-4 are currently being developed by Physical Optics Corporation (POC). CIT provides high-resolution, three-dimensional (3D), Compton scattered X-ray imaging of the internal structure of evaluated objects, using a set of acquired two-dimensional Compton scattered X-ray images of consecutive cross sections of these objects. Unlike conventional computerized tomography, CIT requires only one-sided access to objects, has no limitation on the dimensions and geometry of such objects, and can be applied to large, multilayer, nonuniform objects. Also, CIT does not require any contact with objects during its ...


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